Making his final Cactus League start before he steps on the mound Monday in Milwaukee for the regular-season opener, the Rockies’ Jhoulys Chacin got lit up by the A’s Wednesday afternoon.

The A’s, who inserted Triple-A players into the game after the first inning, raked Chacin for six runs on 10 hits in five innings. Chacin, who needs to keep his slider and sinker low in the zone to be effective, left too many pitches floating over the plate.

“Jhoulys wasn’t as sharp as he’s been at times this spring,” manager Walt Weiss said. “He had to pitch out of some trouble, and he labored a little bit, but he got his work in.”

Chacin finished his spring with an unsightly 8.44 ERA, yet even with the opener five days away, Weiss said he’s not worried.

“Jhoulys has got to command his stuff, and I’m not concerned that he will do that,” Weiss said.

When Chacin is on, he throws a very good changeup and keeps his fastball and slider low in the zone. He wasn’t on, and he wasn’t low, on Wednesday.

“He was up a little bit too much today,” Weiss said. “He’s got to get strikes with his fastball and get outs with his changeup, but he labored a little bit today.”

HITS: Dexter Fowler and Troy Tulowitzki are regular-season ready. Fowler led off the first and the fifth with solo homers. He’s swatted four home runs this spring, to compliment his .388 average.

Tulo finished the day 3-for-4, coming up a triple short of the cycle. His solo homer in the fifth was a line drive off the signage in left field.

Chris Nelson, now the clear front-runner to win the starting third-base job over prospect Nolan Arenado, hit his second homer. He finished 1-for-4 with two strikeouts, his average dipping to .264.

Tyler Colvin’s tough spring continues. He went 0-for-2 with a walk and his spring average is down to .167.

UP NEXT: The Rockies finish the Arizona portion of their exhibition schedule on Thursday with a game against the Brewers at Salt River Fields. First pitch is scheduled for 2:10 p.m. (MDT). Lefty Jorge De La Rosa is in line to start for Colorado, but since the Rockies play the Brewers next week, he’ll likely pitch a minor-league game instead. Newly-signed Kyle Lohse (three years, $33 million) is scheduled to start for Milwaukee.

The Rockies are off on Friday before traveling to Salt Lake City to face the Mariners on Saturday in their final exhibition game.